In sunny, windy, sweltering weather Sunday, Ferrer held every service game and improved to 22-4 this year. He leads the men’s tour in victories.

The Spaniard improved to 6-0 against Fognini, including three victories this year, and reached the fourth round at Key Biscayne for the eighth time. Ferrer next faces No. 13 Kei Nishikori, who beat Xavier Malisse 6-2, 7-5.